1. Field of the Invention
The present invention relates generally to the sawing of boards from logs, and more specifically to an improved edger saw mechanism for sawing at least one edge from a board.
2. Description of the Prior Art
Edger saw mechanisms for sawing one or more edges from a board as it is being sawed from a log to form a finished board are well known in the art. Such edger saw mechanisms have circular edger saws spaced a set distance apart for sawing the edges of a board to obtain one or more finished boards of a finite width. The edger saws are mounted to lie in vertically spaced horizontal planes for sawing the board edges along horizontal kerf lines as a log is transported on a horizontal flat bed of a carriage past the edger saws.
As is well known, logs cut from certain trees are not always straight or generally cylindrical. In many instances, such logs vary greatly in diameter from one end to the other and are not symmetrical about the log axis, which in turn may not be straight. The non-symmetry is due, for example, to irregular knots and other projections on the periphery of the log.
When an irregularly shaped or non-symmetrical log is transported past a head saw for the first time in a board sawing operation, a bark segment of the log is sawed off exposing a face side of the log. When the carriage is returned, the edger saws are positioned to saw off the bark edges or wane when the log is again transported past the head saw to saw a finished board from the log of a finite width. A problem in sawing boards from certain irregularly shaped logs with the prior known edger saw mechanisms is that it is impossible to saw a finished board from the log of the largest width possible. This is so because the edger saws can only saw the board edges along horizontal lines whereas the bark edge or wane may be angled to the horizontal. What occurs, is that the board sawed from the log is smaller than could possibly be achieved, resulting in a reduced board quality and/or board area obtained from a log.